The Cancer Center Mass Spectrometry Core will identify and quantify proteins that change expression in well characterized protein fractions from cancerous cells or tissues. This will include identifying and quantifying changes in binding partners and post-translational modifications. Column chromatography and gel electrophoresis based one and two dimensional separations of protein complexes coupled to mass spectrometry will be used. Techniques such as difference gel electrophoresis (DIGE), isobaric tag for relative and absolute quantitation (iTRAQ) and 180-labeling will be available for quantify relative differences in protein expression. This Core will provide a senior staff technician to assist Center investigators and their staff in preparing and analyzing their samples.